Rome, the Eternal City.
Today, it's a place dominated by Christianity.
Its churches rule the skyline.
Its faithful pack the streets.
Every year, thousands upon thousands of pilgrims
from across the world flock here to worship in the place
that is truly the beating heart of the Catholic faith.
For many, Rome's status as a holy city begins with Christianity.
But in fact, its origin as a sacred site
owes everything to its pre-Christian past.
It was exotic pagan deities who were first credited
with transforming a hillside village
to the capital of the most powerful empire the world has ever known.
These were the gods of thunder, love, war and wisdom,
who dominated the city for a thousand years
and held its fortune in their hands.
The very ground Rome was built on was considered sacred,
from its temples...to its sewers.
You can smell putrefaction, the sweetness of waste.
But it also stinks of history. It's a secret world lost in time.
This is a city I've always been drawn to.
And in this series,
I'm going to be discovering just how it gained its tradition of holiness.
I've come with the questions of both historian and tourist,
to examine the fabric of a place
where power and religion go hand in hand.
Rome has always been inspired
and shaped by its passionate sense of sacred mission.
Popes and emperors, kings and consuls have all believed
they served a higher purpose, to fulfil the will of the divine.
And in this episode, I'm going right back to Rome's pagan roots,
to a world of empires won and lost, holy ambitions fulfilled,
a place where signs from heaven could change the course of history
and men became gods.
I want to find out just how this once-marshy wasteland
became one of the world's holiest cities.
Every July, Rome celebrates one of its favourite festivals.
It's a Catholic celebration in which a statue of the Virgin Mary
gets a tour of Rome along the River Tiber.
And she's off.
It's quite a bizarre sight,
the mother of God, taking a ride on a motorboat.
But it does sum up Rome today.
Here, religious pageantry is the city's daily theatre,
on the streets and on the water.
Christianity rules the Holy City.
But everywhere you look, paganism lurks just beneath the surface.
Images of Mary on street corners were once pagan shrines
devoted to the household gods.
Ancient temples have been absorbed
into the fabric of Christian churches.
And the Pope has a pagan precedent.
The ancient Romans had their own high priest, the Pontifex Maximus.
Even this procession has echoes of the pagan world.
In 205 BC, there are stories of the Magna Mater,
a foreign goddess, being brought into Rome by boat
right up this river, just like this,
except it wouldn't have been motorboats.
It would have been wooden boats.
It wouldn't have been balloons, it would have been incense lamps.
But the modern, Christian Rome of today, in many ways,
is not so far removed
from the ancient, pagan Rome of gods and emperors.
And there's a clue to the origins of Rome's timeless sanctity
in its founding myth.
Every sacred city needs a creation story, and Rome is no different.
It's a tale that defined the ancient Romans.
And as a tourist, it's a legend you still can't escape.
There are glimpses of it just about everywhere.
And here it is, two children suckling a she-wolf.
It's a timeless vision of human dreams and nightmares -
lupine ferocity meets maternal nurture.
But it sums up everything the Romans wanted to believe about themselves
and their city's destiny.
According to myth,
Rome was founded in 753 BC
by the twin brothers Romulus and Remus.
Abandoned as babies, they were rescued by a she-wolf.
And once adults, they decided to found a city.
But it wasn't that simple.
Being brothers, they soon fell out over where to build it.
Romulus wanted to build it on the Palatine Hill.
Remus wanted to build it on neighbouring Aventine Hill.
And to make the right decision, they decided to consult the gods.
Signs from heaven were sent to each brother in the form of vultures.
Remus saw them first, six birds over the Aventine.
But Romulus saw more, twelve.
Each brother claimed the gods favoured him.
It was a rivalry with fatal consequences.
Romulus started to build walls around the Palatine
to mark the boundaries of his new city.
Remus mocked his brother by jumping over the half-built fortifications.
It was a challenge, and Romulus answered it by killing his brother.
The gods had spoken.
It's a legend that reflects the Roman conviction
that this was a city whose fate was divinely ordained.
So the story of Rome begins, with religious omens
and murderous ambition, power and religion -
the essential ingredients of a holy city then, and now.
Of course, the story is a legend.
And the archaeology shows that Rome actually started as a patchwork
of small farms on the seven hills overlooking the River Tiber.
Between the hills,
there were marshy valleys where the local people buried their dead.
Some time in the eighth century BC,
two villages that stood on the hills,
the Palatine and the Quirinal, merged into one settlement.
But there is one element in the Romulus and Remus story
that does seem to have a basis in historical fact,
and that is that right from the beginning,
Rome was surrounded by a boundary that was of enormous importance.
It marked Rome out as a sacred city.
This boundary was known as the Pomerium,
and Romans thought it originally followed
the line ploughed by Romulus around the city.
But it wasn't just about marking out territory.
Much more significantly,
the Romans believed the land within it enjoyed divine protection.
This gateway, known as the Arch of Dolabella,
was built on the line of the Pomerium.
And to keep the gods happy,
there were strict rules dictating behaviour
within Rome's sacred confines.
So on this side of the arch was outside the city,
where the Romans believed you could bury your dead or make war.
But as I walk through the archway, I enter Rome.
Rome begins here, and everything is sacred.
So if I was a soldier, for example,
I would have to leave my arms outside the gate.
Generals could not build military camps here.
The Romans believed that to break these rules was sacrilege.
And this idea of what is and isn't sacred space
has influenced the way the entire city has been laid out.
It's why one of the main thoroughfares into Rome,
the Appian Way, is lined with tombs.
But only up to a certain point.
They stop the moment you enter the city itself.
It's also why the tombs of the early Christians, the Catacombs,
and on the outskirts and not in the centre.
But the sacred space in Rome wasn't just what you saw around you,
it also extended beneath your feet, right underground.
Deep below the is one of its most secret and holy sites.
It's a network of some sewers,
but they weren't just to wash away the effluence of the Romans.
Like everything else in this city, they also had a sacred purpose.
They were said to be the brainchild of one of Rome's earliest rulers,
Tarquinius Priscus, fifth monarch of the city,
and one of a line of kings who ruled here.
The entrance to the sewers is in the Forum of Nerva.
It's here that I met up with Mark Bradley,
for whom they are a personal passion.
Truly an elegant look for la dolce vita.
The sewers are still in use today, so precautions have to be taken.
How do I look?
I think we're ready to face the effluvia of the ancients.
But I quickly realised that penetrating these faecal caverns
wasn't going to be easy.
No way! I don't think I can go down there.
I hate to tell you this. I'm serious.
Nobody's ever fallen down it.
Don't like the look of it.
Half an hour later, after a very 21st-century panic attack
that would have shamed the noble Romans,
I managed to face this terrifying abyss.
And as I descended into this twilight canyon of filth,
I could smell it before I could see it.
What a place! Oh, my God!
What is that?
This is absolutely extraordinary down here.
Yes, these are terribly, terribly important.
This is the Cloaca Maxima, the great sewer,
which is the oldest surviving intact monument in Rome.
Forget all the temples, all the palaces,
this is the real start of Rome.
One of the main functions of these sewers originally was to drain
the Forum, which was being periodically flooded by the Tiber.
It's massive. You can sail a boat through here.
And the Romans boasted about sailing boats through here.
Come on, let's explore.
This extraordinary sanitation system was built
right back in the sixth century BC.
And its tunnels stretch for miles and miles.
For 2,500 years, right up until the 19th century,
this was the only sewer system serving the whole of Rome.
And the ancient Romans believed it purified the city,
both practically and symbolically.
So, Mark, why are these sewers sacred?
Well, these sewers are sacred, in part, because they flush waste
out of the city, they cleanse the city, they make it pure.
And there are shrines marking particular points
and junctions in the sewer.
There is a very long-standing tradition in the history of Rome
where unwanted elements of society -
so criminals, deposed tyrants, even Christian martyrs - would be
cast down here, symbolically, to be flushed out of the city.
Which emperors were actually tossed down here?
The one emperor who is very famous for this is the Emperor Elegabalus
in the early third century AD,
who was a depraved young emperor who made a complete mess of Rome.
He was eventually assassinated, his body was dragged, really foully,
through the sewers and evacuated outside the city.
That's all that's left of one of the last people to be here.
The Romans believed this purging of the city
was key to its very survival.
If Rome was pure, the gods would be happy.
And the city's fortunes would be secure.
I actually didn't think I'd be able to get down here,
but I'm so pleased I did. I love it.
The stones themselves speak, perhaps I should say stink, of history.
However disgusting it is down here - and it really is disgusting -
the walls, the liquid, the stink is appalling.
It's sweet in its horror.
And yet I have to tell you there is real grandeur down here
and it is the sacred grandeur of ancient Rome.
This splendid subterranean world has shown me
that right from its inception, Rome was regarded as a holy city,
above and even below the surface.
Oh, my God! How lovely! Sunlight, air!
Goodbye, ancient tunnels of Rome.
The sewers are one of Rome's best-kept secrets.
But they have an unexpected link to one of the city's
most popular tourist destinations that might not please
the thousands of people who come here.
The famous Bocca della Verita, the mouth of truth, has been linked
since Middle Ages to a tradition
that if an unfaithful lover put his or her hand in the mouth,
it would be bitten off.
In Roman times, it wasn't a good idea to put your hand in that hole,
whether you were faithful or not.
This is in fact a monumental sewer cover,
decorated with the face of Oceanus, God of the oceans.
The risk was not so much from infidelity as from infection.
The concept of Rome as a holy city was present from the beginning.
And it not only shaped how the Romans designed their city,
it also influenced every political decision its rulers made.
The Romans were obsessed with the gods and their moods.
And that governed how they behaved from dawn till dusk.
Every soldier, every Caesar, believed he had a religious role.
To commemorate the greatness of Rome was to celebrate its holy destiny.
In this city, religion and politics were inseparable bedfellows.
Nowhere is this marriage of sacred and secular more blatant than here.
At the Forum, the heart of pagan Rome.
It was first built in the sixth century BC as a civic centre
after the sewers were established and the land drained.
And for 1,000 years, it was the centre of Roman public life.
Here, speeches were given, criminals were tried, laws were made.
And temple after temple was raised to the glory of the gods of Rome.
According to legend, this was home to another king of the city,
whose influence shaped the earliest traditions of Roman life.
His name was Numa Pompilius.
The Romans believed that it was Numa who created
the religious rituals and structures that made possible the rise of Rome.
And he did it right here.
When you visit the Forum for the first time,
you're both dazzled and bewildered.
It's a mishmash of architectural fragments from different ages.
There are traces of temples built and rebuilt.
Layer upon layer of Roman history.
Much of what stand here today belongs to the time
of the emperors, the last leaders to make their mark.
But the origins of this site can be dated right back to
the period of the Roman monarchy.
King Numa was said to have established four colleges of priests,
with very clear responsibilities.
They were not just religious, they were also political.
And without their say-so,
the entire routine of Roman politics would grind to a halt.
All buildings in the Forum, public or private,
were dedicated to the gods.
And all political decisions had to be made
on sanctified ground - from holding elections to passing laws.
So it was a group of priests known as the augurs
who had the final say over planning decisions.
This was the Senate house,
but it was also something called a "templum", a sacred space.
The augurs would consult the heavens to approve the site
and then map it out with holy staffs.
It was as if the Houses of Parliament
stood on a sacred rectangle.
And if the space wasn't sacred, the decisions weren't valid.
At the opposite end of the forum was the Regia.
It was the royal residence,
originally thought to be the Palace of King Numa
and the seat of secular power.
But it was also the centre of religious control.
This was once the headquarters of the Pontifex Maximus,
the high priest, the supreme religious authority of Rome
and Pontifex Maximus literally means "the greatest bridge-builder".
He was the bridge between gods and men.
He regulated the rituals of Roman life and the divine law
and this gave him considerable political authority.
But he was also a master of the Vestal Virgins
and right next door to his headquarters
was their house and temple.
The Virgins were priestesses of Vesta,
the goddess of the hearth and home,
who had a special link to the fortunes of the entire city.
The Vestal Virgins were chosen at the age of six
for their moral and physical perfection.
Their task was to tend the sacred flame
of the sacred hearth of the city
and the Romans believed that if the fire went out
the city itself would fall.
The whole forum was a place where religious practice
ensured Rome's political decisions had divine backing.
I've always been fascinated by the macabre rituals
that really decided the destiny of Rome.
So I asked Mark Bradley to give me an insight
into the work of a priestly group who were involved
in one of the gorier aspects of Roman politics -
they were known as the haruspices,
diviners from the Etruscan communities of northern Italy,
skilled in interpreting signs from the gods.
And there's a reason we're meeting in a fresh food market.
So, Mark, what is this still-warm, almost pulsating bloody organ
that we have here on the platter in this butcher's shop?
Well, this is a fresh liver taken from a newly sacrificed sheep.
What the priests would do is they'd cut open the animal
and they'd take out the liver while it was still pulsating
and they'd examine it to see what the future has in store.
So the first thing we need to do is orientate it correctly.
What the haruspices did is they used a model of the liver
to guide them, to remind them, to prompt them about how to read it,
so what we have here is a bronze model of a liver
from about 100 BC and this is called the Piacenza Liver,
and on this you can see the gall bladder, the caudal lobe,
and the liver was divided into 16 sections
and these 16 sections corresponded to the 16 regions of heaven
and each region was governed over by a particular god.
So what we'll do is we'll have a look at this liver and see what it tellsus.
So this area here, around where the gall bladder was,
is an area governed by war gods
and if you find a discolouration, a tumour, a blood clot,
a bile pool or something like that in this area,
that might mean that the war gods are not happy,
this might not be a good time to go to war.
Another area that's very interesting is all of this area
which is associated with the Etruscan god Tin,
who is the equivalent of Jupiter in Roman cult.
If he's not happy you need to make a sacrifice to him
or you need to build a temple to him or something like that.
OK, so if I'm an emperor, my legions are massed
and I now want to invade Germany today and destroy the German tribes,
can I march today? Can you read the organ?
Well, this liver is remarkably clean.
This is absolutely unblemished, as far as I can see.
This is a good time to do pretty much anything.
I'm happy, call in the centurions - we march today. Absolutely.
If religion was an essential part of a politician's life,
for your ordinary Roman there was barely a beat in the day
that wasn't overseen by a god.
Buon giorno.
For the average Roman farmer,
it wasn't just about sowing, ploughing and reaping.
To get a bumper harvest they had to keep the gods happy, too.
In April there was the Festival of Cerialia
dedicated to the goddess of grain,
which involved heading out to the Circus Maximus in the evening
to watch foxes with torches tied to their tails.
This, apparently, protected the crops from vermin.
And then there was the Festival to the god Robigus who governed mildew.
To avoid an outbreak, farmers had to sacrifice a dog.
And in October, to thank Mars for the harvest,
it was a horse that got the chop.
And private rituals were as important as public festivals.
Families prayed daily to the household gods, the Lares,
whose statues they kept at home in special niches.
And they gathered for ceremonies in the fields to offer sacrifices,
ensuring the crops would ripen.
In fact, the Roman farmer had so many religious obligations
it's a wonder he had any time to tend his crops.
The religious structures and practices said to have been established by King Numa
largely formed the basis of Roman religion
for the entire first millennium of Rome.
But in 509 BC a political crisis broke out.
A group of aristocrats rebelled against the king, Tarquin the Proud.
They overthrew him and established a new political system.
Rome would no longer be ruled by one man but by the Senate,
an assembly of its leading citizens.
The Roman Republic was born.
But whatever ideas drove the change,
religion remained at the heart of the new regime.
Indeed, the more successful Rome became, the more sacred the city.
The dawn of the Republic was marked by an event
that would have seen the whole of Rome celebrating on the streets.
It was the dedication ceremony
of a building that once stood here on the Capitoline Hill.
The single most important temple ever erected in Rome.
On 13 September 509 BC,
this spot above the forum would have been packed with people.
And what an awesome spectacle it would have been.
They were there for the dedication of the vast new temple of Jupiter,
Optimus Maximus, the biggest and brightest of the Roman gods.
There was an altar outside for sacrifices
and the doors were always open
so passers-by could see the huge and gaudy statues of the gods within.
For a Roman who was there that day
it would have been as magnificent as it was unforgettable.
The entire ceremony was designed to remind the Roman people
that the god Jupiter was the source of Roman glory.
And for the new Republic,
this building marked a dramatic moment in the city's history.
This was the opening ceremony
of the first pagan cathedral of republican Rome.
The only surviving sections of the temple
are now in the Capitoline Museum in their original position.
Matthew Nicholls believes it is a building
that encapsulates the sacred ambitions of this new regime.
What we're looking at here, Simon,
is a wall that forms part of the foundations of the Temple of Jupiter.
It's not the temple itself, it merely the foundations
that built a huge platform on which the temple sat.
And how big was it? It was enormous. It was awe-inspiringly huge.
You've got to imagine a podium that was perhaps the size
of two Olympic swimming pools side-by-side
with the temple itself sitting up on top of that.
So this dominated central Rome? This dominated the forum?
It looked down on the forum,
it looked out across the hills and valleys of Rome.
It could be seen from a long way away and it was a magnificent sight.
Who built it and what was its political significance?
Its significance is really what it tells us
about the ambitions of the Roman state.
It was linked right from the start to conquest
and the divine mission of conquest the Romans felt they had.
But even though we associate this temple very closely
with the Roman Republic and the many rituals of the Republic,
in fact it was planned, it was conceived,
when Rome had kings, was ruled by Etruscan kings,
and the last of them, Tarquinius Superbus,
was responsible for almost bringing this temple to fruition,
and then his rule was blown away in the revolution.
So why did the Republic adopt this very royal enterprise?
Romans loved the idea that their rule and their growing empire
was sanctioned by the will of heaven, that this was a mission
that the gods entrusted to them as a people.
Even when the kings were gone, the Roman people could carry that mission forwards.
The building of this temple
marked a watershed in the history of the whole city.
It was the moment when Rome transformed
from being a town of small-scale temples and shrines
to a sacred capital embellished with its own cathedral.
The Temple of Jupiter was a declaration
of the astonishing religious and political confidence of Rome,
a rising power blessed and propelled on its sacred destiny
by the forces of the gods.
And that power was consolidated by the raising of ever-more temples.
Their remains can still be seen all over Rome.
As the Romans conquered new territories,
the spoils of victory poured into the city
and since the Romans attributed their success to the gods,
so the victors built more and more magnificent temples
in gratitude and in celebration.
Gradually the geography of the Holy City
began to resemble a map of Rome's ever-increasing empire.
And nowhere was Rome's acknowledgement of the gods clearer
than in one of the city's most colourful military ceremonies.
When a general returned from a victorious war,
the Senate voted him something called a Triumph, a parade through the city.
He rode in his chariot followed by his army,
by wagons heaped with booty
and by his shackled prisoners
and he ended up right here at the Via Sacra, the Sacred Way,
the most important street in the Roman forum.
Imagine the excitement.
The general wearing purple and gold, his face painted scarlet.
He was dressed as Jupiter for a day,
but in case the glory went to his head,
a slave rode behind him in his chariot whispering,
"Remember - you are only mortal."
His procession ended, of course,
at the Capitol and the Temple of Jupiter
where he laid laurels at the feet of the giant statues of the gods.
At that moment there'd be no doubt in any Roman's mind
that the gods were responsible for the city's fortunes.
But the success of the Republic came at a price.
It was the purity of Rome's religion that suffered.
The city's expansion into a vast empire
led to an influx of foreigners from Greece to Egypt.
And with them came their gods.
Rome's senators could have suppressed these new divinities
and stayed faithful to their own,
but they took a more pragmatic approach.
Foreign gods, like Isis and Serapis,
were absorbed into the state religion and in the third century BC
one was even imported to try and avert disaster.
In 205 BC, Rome faced one of its gravest crises.
For almost a century, the city was engaged in a power struggle
for control of the Mediterranean.
Its enemy was Carthage, led by the brilliant commander Hannibal.
And it was a threat that led to the introduction
of one of the most flamboyant and exotic new goddesses to the city -
just in the nick of time.
Rome's very existence was in peril.
Strange portents and mysterious hailstone storms threatened danger
and in their panic the Romans decide to consult the Sibylline Books,
sacred texts kept in the great Temple of Jupiter.
Their advice was clear -
in order to avoid defeat by Hannibal and the Carthaginians,
the Romans must import a foreign goddess from Asia Minor.
Her name was Magna Mater, the great mother,
and her arrival in the city
and her acceptance as one of its official gods -
that alone would help save Rome.
The Roman historian Livy wrote a vivid description
of her arrival in the city.
The goddess was shipped up the Tiber
accompanied by her cult officials known as the Galli -
self-castrated eunuch priests.
And when she arrived at the river's bank
she was born through the city, passed from hand to hand.
The whole of Rome came out to meet her.
Incense burners lined the streets
and all the Romans prayed that she would enter the city willingly.
It seems Rome hasn't changed as much as you might think.
LOUDSPEAKER CHANTS
Shortly after her arrival,
Magna Mater was given a home at the very centre of the city -
a temple on the Palatine Hill -
and her rituals were incorporated into the official calendar.
Three years later, Hannibal was defeated.
The story of Magna Mater shows how far Rome had come.
It transformed from sacred village to a holy city
dedicated to a multinational pantheon of deities.
But in the first century BC, 700 years after its foundation,
the whole city was to become a shrine
not just to the gods, but to a man.
And one man in particular.
It was an innovation that had its roots
in the rule of one of Rome's most outstanding leaders...
..Julius Caesar.
Caesar's rise to power came at a time when violence,
cynicism and corruption had taken hold of the Holy City.
As the empire grew, the struggle for control became more and more vicious
and religion was ripe for exploitation.
Portents from heaven were interpreted to justify decisions.
Omens and oracles were invented for political advantage.
And in this world, one man stood out.
Caesar was so exceptional,
the Roman state was almost too small for him.
Nicknamed by his own soldiers "The Balding Adulterer",
he was a gambler, a risk-taker,
and he was an arch manipulator of religion
for his own political ends.
He even claimed to be descended from the goddess Venus herself.
But his success provoked the jealousy and suspicion of the other nobles
with deadly consequences.
This little-known square is the closest you can get
to the spot where Caesar was murdered.
In the first century BC, these ruins were temples.
And on the Ides of March 44 BC, Caesar was passing here
when he was stabbed by a group of conspirators.
At first he fought back,
but when he saw among the assassins was Brutus,
his mistress's son whom he adored, he gave up.
His murder was meant to save the Republic,
but in fact it just accelerated the end of the dream.
With Caesar's successors,
Rome would no longer be ruled by the Senate as a republic
but by a single ruler as an autocracy.
And with this new political order came an innovation in Roman religion
which would once again have a huge physical impact on the Holy City
and on the daily lives of the ordinary people who lived here.
The Emperor wouldn't just be
the most powerful political leader in the western world -
he was about to become the son of a god.
Caesar's heir was his 18-year-old nephew, and adopted son, Octavian,
a brilliant political strategist, who combined the old and the new
to give Roman leaders a new status.
They were no longer just generals and priests -
they could also be gods.
After Caesar's death, Rome was thrown into chaos
and a fight for power ripped the city apart.
Octavian found himself in a bitter struggle to rule the Empire
against Caesar's right-hand man, Mark Antony.
Mark Antony allied himself with the irresistibly vampish
and hugely ambitious Queen of Egypt, Cleopatra.
Together, they embraced an Eastern version of power and religion.
But Octavian cleverly used this to turn the Romans against them.
Antony and Cleopatra were defeated in battle and committed suicide.
He by sword, she by snake.
And Octavian became Rome's first emperor.
Octavian's victory marked a crucial turning point in Rome's history.
Under his regime, it became the most magnificent
and sacred capital of the Western world.
Romans began to call it "the eternal city".
And Octavian had similarly grand ideas about his own status.
When Octavian became emperor,
he adopted a new name for his new role - Augustus Caesar.
Augustus means "consecrated by the augurs".
It was a name that evoked the favour of the gods
and the auspices that marked the founding of Rome.
The name Caesar also linked Augustus to his murdered uncle, Julius.
And very early on, he had a temple built here, in the Forum,
in his uncle's honour.
It doesn't look like much now,
but this once dominated the entire south side of the Forum.
Before it was built, this was where they brought Julius Caesar's body
after his assassination.
And it was here that they cremated him before huge crowds.
The temple marks a major change in Roman religion.
This is when they started to treat their rulers not as men,
but as gods.
On 1 January 42 BC, the Senate passed an unprecedented decree.
They declared Julius Caesar divine.
It made him the first historical Roman ever to be officially deified.
With a temple and priests, this mere mortal had now become a god.
And if Julius Caesar was a god, then his adopted son, Augustus,
had a new title - Divi Filius, son of a god.
But Augustus's desire for divinity wasn't satisfied by a title alone.
He spent the next four decades taking steps which gradually tied
Roman religion not just to the city of Rome, but to a single person -
the Emperor.
And he did it through a vigorous programme
of rebuilding and religious renewal.
He reinstated ancient religious festivals,
rebuilt crumbling temples, filled vacant priesthoods.
He claimed he was restoring Rome's ancient past to please the gods.
What he was really doing was making Rome his own.
Augustus subtly co-opted new powers,
taking on the mantle of all the major priesthoods in Rome,
culminating in 12 BC,
when he declared himself Pontifex Maximus.
Five years later, he divided the city into new districts.
And on every street corner, he built a shrine.
In his meticulous way,
he was altering the whole focus of Roman worship.
Very few traces of these ancient shrines remain,
but there's one in the Vatican Museum.
It's tucked away from public view in the Pope's own private gallery.
And its carvings show just how the shrewd Augustus was shifting
the object of Roman worship from the gods
to himself and his own family.
SPEAKS IN ITALIAN
So, what are the images on it?
And Augustus's family connection to the gods
is even more explicit in another scene.
What did Augustus want the people who saw this shrine to believe?
By putting images of his deified ancestors on shrines all over Rome,
and encouraging sacrifices to them,
Augustus was making a bold statement.
Augustus was inviting all ordinary Romans
to take part in the creation of a new imperial mythology.
The city of Rome was being indelibly stamped
with the divine claims of one family, one ruler.
And Augustus set the tone for the emperors who came after him.
During his life, he was the sole religious authority in Rome.
And on his death, by vote of the Senate, he too was declared a god.
The Forum is a living testament to Augustus's precedent.
Temples to the deified emperors would soon dominate this sacred space.
So here is the temple to the Emperor Antoninus Pius.
And here, these columns were the temple to the emperors Vespasian and Titus.
Now, Vespasian, who was a bluff soldier,
kept a sense of humour about divinity.
When he lay on his deathbed, he joked,
"I think I'm about to become a god."
But other emperors lacked his sense of detachment.
The demented emperor Caligula cavorted as the goddess Venus
in a gorgeous bejewelled dress.
The emperor Hadrian took all of it a step further
when he deified his young gay lover.
And as for Nero, he built a 120ft statue of himself as the sun god,
right here in the centre of Rome.
But it was the imperial cult and its demands that provoked a minor challenge
to Roman religion, with world-shattering consequences.
A new generation of foreign sects
were starting to gain popularity in the city.
And one in particular showed resistance
to this worship of emperors.
That cult was, of course, Christianity.
And 300 years after its emergence,
it would entirely reshape the city of Rome.
The pagan temples would be converted into churches,
leaving the Roman gods to crumble into dust.
But when it first arrived in Rome, in the first century AD,
Christianity looked less like a force to be feared
and more like a sect of cranks with peculiar
and preposterous beliefs, worthy of mockery.
And there's a glimpse of just how unthreatening the pagan Romans
initially thought the Christians were
in a rare piece of ancient graffiti,
uncovered by archaeologists in the 19th century.
So here it is.
It's very small and it's very hard to see,
and I find it absolutely fascinating.
What we have here is a human figure being crucified on the cross.
What's bizarre about it is that the person being crucified
has the head of a donkey.
There's a figure, apparently worshipping beside the cross,
hand raised, possibly a soldier,
and, underneath, it says, "Alexamenos worships his God."
Now what's remarkable about this is it's the first ever
representation of the Crucifixion in history.
What's interesting is that it's clearly
not by a Christian at all, but by a pagan Roman.
The graffiti dates from between the first and third centuries AD
and, at that time, the symbol of the cross wasn't something
the Christians were proud of.
Crucifixion was a shameful death - the method of execution
for the lowest criminals, like showing someone today with
a noose round their neck, and, in the earliest Christian art,
the cross doesn't appear at all, so this pagan graffiti artist
is deliberately mocking and insulting Christian worshippers.
To show Jesus with a donkey's head is the cruellest cut of all.
And donkey worship wasn't the only tittle-tattle
circulating about the Christians.
They were also rumoured to practise magic,
indulge in ritual cannibalism and even incest.
It was all good gossip for the Roman on the street,
but within 200 years, rumour had turned to concern.
As Rome's elite realised, this new sect was persistent
and potentially dangerous.
The Christians were well-organised, they recruited thousands
of new followers, but, worst of all, they refused to take part
in the Roman state religion,
claiming that they worshipped only one God.
They were beginning to look less like a bunch of harmless
and superstitious eccentrics and more like a movement
of defiant subversives who could no longer be controlled.
The Roman elite had in the past tolerated foreign gods,
but they were always clear that whatever people's private beliefs,
public loyalty to Roman religion came first.
After all, the fortunes of the city
were at the mercy of the pagan gods -
snub them and the consequences could be catastrophic.
So if a group like the Christians failed to pay due respect,
how would the gods react?
The fate of the city and its Empire hung in the balance.
And in the third century, it seemed as if their fears were justified.
The Roman Empire was beset by invasion,
civil war and economic depression.
It was on the verge of collapse...
..until the reign of a new emperor - Diocletian.
He was a superb general, who restored order by conquest,
reform and restoration of the old gods...
..but one sect resisted.
And when Diocletian's palace burned down
and the army's sacrificial portents looked bleak,
the Christians were blamed for failing to honour the Roman gods.
Diocletian decided to solve the problem by force. In 304 AD,
he ordered every citizen of the Empire to sacrifice publicly
to the Roman gods, and if the Christians refused,
they would be executed.
It was a strategy designed to drive the Christians into the open.
Yet, despite the threats, they remained defiant.
Rome's senators were baffled.
Why would anyone risk their lives for this upstart cult
whose founder died a criminal's death in a Roman outpost,
when the pagan gods had delivered the riches of Empire?
Yet, still, pagan Romans were choosing to convert,
and here in the suburbs of Rome,
there's a fascinating clue as to why.
This is the Catacomb of Priscilla where Christians were buried
in the first centuries of the church,
and it's one of the few places in Rome
that they left their mark -
the walls are covered by their paintings.
And there's one that gives an insight into just why pagan Romans
were choosing to face execution for this new Christian God.
So here it is.
This is a biblical scene from the Old Testament Book of Daniel
and it tells the story of these three Jewish characters
who were in exile in Babylon from Israel.
They refused to pray
to the image of the king of Babylon, Nebuchadnezzar and, as a result,
they were sentenced, as you can see,
to die horribly in this fiery furnace.
Parallels for Christians facing persecution in Rome were clear,
but there's a twist to the biblical story which gives this image
another dimension.
What's surprising about this is that if you look closely,
these characters are praying, but they're not burning.
The Book of Daniel says that they were able to walk
unscathed among the flames and emerge entirely unharmed.
Their God had saved them.
Now, for Christians, this had another layer of meaning.
The Christian God would not only save Christians from persecution,
he would also save them from death itself.
Christianity offered eternal life.
And this belief in eternity had huge appeal in this pagan city.
For your average Roman, life expectancy was only 29
and daily life was hard.
For the poor, the slaves,
the Pagan Romans at the bottom of the pile, this Christian idea of
a new life after death offered hope
amidst the grind of unrelenting poverty.
The Roman gods may help you conquer an Empire,
but they didn't offer immortality.
It was a masterstroke.
Rome's leaders might be worshipping its pantheon of pagan gods
but some of its people were starting to look elsewhere.
Ancient Rome has always been a symbol of secular power,
but you can't understand the might of this city without also
grasping the sacred beliefs of the Romans themselves.
Right through its history,
Rome's greatness was inextricably linked to its sacred mission.
For its first thousand years, Rome's palaces and temples expressed
one thing - this was a holy city,
blessed by the gods to rule the world.
But all that was to change.
A new god was about to take Rome.
Next time, Rome's transformation from pagan heartland
to the capital of Christendom,
as religious revolution hits the holy city.